Method of dispersing calcium carbonate in a non-volatile carrier



lVIETHOD OF DISPERSING CALCIUM CARBONATE IN A NON-VOLATILE CARRIERRobert L. Carlyle, Lake Jackson, Tex., assignor to Continental OilCompany, Ponca City, Okla, a corporation of Delaware No Drawing; FiledDec. 19, 1 956, Ser. No. 629,229

22 Claims. (Cl. 252-18) cating oil compositions for use in diesel andlike internal combustion engines, at least two requirements must be metby such oils (in addition to lubricity, stability, and the like) if ahigh degree of engine cleanliness is to be maintained. First, the oilmust possess the power to disperse insolubles formed by fuel combustionor oil oxidation, or both; and second, the oil must be capable ofneutralizing acidic lacquer precursors formed by either oil oxidation orinteraction of the oil with sulfur acids produced from fuel combustion,or both of these conditions.

Many attempts have been made heretofore to produce substances whichpossess an alkaline reserve whereby the acidic materials formed inlubricating oils during use may be neutralized. One proposed method isthat described by Bergstrom in Patents 2,270,577 and 2,279,086 utilizingbasic soaps. These basic soaps demonstrated a certam superiority, andfurther attempts were made to increase the basicity of such soaps. Oneof the earliest patents referring to these basic soaps or, as they weresometimes called, over-based soaps or metal complexes is McNab,2,418,894. Other workers in this field include Griesinger et al.,2,402,325. These patentees suggested the use'of a neutralizing agent upto about 220% of the theoretical amount required for the completeneutralization of the acid from which the soap was made. The Work ofGriesinger et al. was followed by Campbell and Dellinger as described intheir Patent 2,485,861. These particular patentees base their disclosureon the hypothesis that minor amounts of alkaline earth metal hydroxideor carbonate can be peptized by means of an oil mahogany sulfonate.Mertes, 2,501,731, described a process whereby the normal soap is firstformed and then anadditional base combined therewith by a more or lesssimple mixing and heating operation followed by filtration.

2,616,924, disclose a process whereby a much larger amount of metal orbase may be combined with the normal soap, thus forming a complex whichmay be dispersed in a lubricating oil and, because of the excess metalpresent, possesses an alkaline reserve. Theinvention of Asseff et al. isan improvement over the Mertes disclosure in that Assefi et al. employeda so-called promoter. Generally these promoters are alkylated phenols.

Van Ess et al., 2,585,520, disclose a process for the preparation of abasic salt by first combining in an anhydrous'state the normal salt ofthe acidic material and an alcoholate of the desired metal. The mass isheattreated for a substantial length of time, filtered, and thenUtilizing the basic disclosure of Mertes, Asseif et al.,

2 g. the alcoholate is hydrolyzed to the hydroxide for the purpose ofproviding a basic product.

Although the products produced by the methods deheating process over arather extended period of time.- Another disadvantage which is even moreobjectionable,

from an operating standpoint is that the sizes ofthe individualparticles suspended in the oil vary greatly, from extremely smallparticles to'particles which in many cases exceed ten microns indiameter. The larger size particles are objectionable for two reasons:(1) their presence imparts a haze to the oil, and (2) it is generallyconceded that if the particles exceed five microns in diameter, theresulting product will have a certain abrasive action upon the metalbearings. Before use the product must, therefore, be filtered.Obviously, filtration increases the cost of operation, and the largerparticles retained on the filter must be discarded.

It is, therefore, a principal object of the present invention to providea process for preparing a stable dispersion of calcium carbonate in anon-volatile carrier which process obviates the disadvantages of theprior art process. It is another object of my invention to provide ahighly useful mineral oil composition utilizing such dispersions. Theseand other objects and advantages of the invention will appear as thedescription proceeds.

To the accomplishment of the foregoing and related ends, this inventionthen comprises the features hereinafter fully described and particularlypointed out in the claims, the following description setting forth indetail certain illustrative embodiments of the invention, these beingindicative however of but a few of the various ways in which theprinciple of the invention may be employed.

Broadly stated, the present invention comprises a process for preparinga stable dispersion ofcalcium carbonate in non-volatile carriercompositions which comprises:-

A. Admixing under atmospheric conditions of temperature and pressure anoil soluble dispersing agent and volatile solven therefor 2. anon-volatile carrier for the dispersing agent I 3. an aliphatic alcoholsolution of an oil insoluble calcium containing base formedby reactionbetween hydrogen sulfide and a calcium inorganic compound wherein theanion of said calcium in,- organic compound is selected from the groupconsisting of oxide and hydroxide radicals.

B. Condensing from such mass at atmospheric pressure an oil insolublecalcium carbonate in particles, the diameter of which are less than .25micron, by passing carbon dioxide through such mass to convert theinorganic gas to carbonate C. Removing the residual solvents and anywater present.

Before proceeding with specific examples illustrating my invention, itmay be well to indicate in general the nature of the materials requiredin the process.

DISPERSING AGENTS Patented May 24, i960 fonate. Usually, the use ofsulfonic acids is preferred for economic reasons rather than separatemanufacture of a sulfonate prior to the dispersion process. By using apreformed sulfonate, it is possible to obtain compositions wherein thecation of the sulfonate dispersant is other than calcium.

Whether sulfonic acids or preformed sulfonates are used, it is desirableto avoid appreciable amounts of sulfuric acid or salts of same in thedispersant. If these contaminants are present, the final products tendto be slightly hazy and require centrifugation or filtration forclarification.

When sulfom'c acids are used, I add from about 1% to 4% times thequantity of the oil-insoluble inorganic compound than will react withthe sulfonic acid, thus insuring the presence of an inorganic compoundin the product as a dispersant.

In most cases sulfonic acids are purified in the presence of suitablevolatile solvents, hence are customarily used in this form in theprocess of this invention. Solvents are desirable to reduce viscosityduring processing. Suitable solvents include low molecular weightalcohols, aromatic hydrocarbons, aliphatic hydrocarbons, and the like.Specific examples include methanol, benzene, hexane, and variouspetroleum distillates such as naphthas, etc.

Sulfonates which are suitable are oil soluble and include alkylsulfonates, alkaryl sulfonates, the so-called mahogany or petroleumsoaps, and the like. The mahogany soaps include particularly theoil-soluble aromatic sulfonates from petroleum. Many of the aromaticsulfonates have cycloalkyl (i.e., naphthenic) groups in the side chainsattached to the benzene ring. The industrial production of oil-solublemahogany sulfonates from petroleum is well understood in the art and isdescribed in the liaterature. Normally, the alkyl sulfonates requireabout 24 carbon atoms for oil solubility. The alkary'l sulfonates,however, require an alkyl portion totalling only about 18 carbon atoms.To attain the requisite oil solubility, therefore, requires that thehydrocarbon portion of the sulfonate have a molecular weight betweenabout 350 and 1,000. Preferably, this molecular weight is between 400and 700. Particularly useful sulfonates include postdodecylbenzenesulfonates, diwaxbenzene sulfonates, diwaxtoluene sulfonates, and polynonyl naphthalene sulfonates; barium and calcium postdodecylbenzenesulfonates being preferred. A particularly useful sulfonate for use inmy invention, because of its availability and commercial importance, isthe sulfonate obtained by neutralizing postdodecylbenzene sulfonic acidwhich in turn is obtained by the sulfonation of postdodecylbenzene.Postdodeeylbenzene consists of monoalkylbenzenes and dialkylbenzenesin'the approximate ratio of 2:3. Its typical properties are as follows:

Specific gravity at 38 0.8649

The wax used in making the wax aromatic sulfonate is obtained fromdifferent sources of crude petroleum oil.

Various grades of parafiin wax are made with difierent melting points.The 126-128" F. (52.2-53.3 C.) melting point wax is a mixture of organiccompounds with the molecular weight averaging in the range of 330-340.The average carbon content of this mixture of organic compounds will bearound 24. As the melting point of the Wax decreases the carbon contentof the mixture will,

average as low as 18 or a littlelower.

Other sulfonates which may be used in the'process of this inventioninclude, for example, monoand po1y-,

NON-VOLATILE CARRIER Suitable non-volatile carriers include mineraloils, highboiling petroleum hydrocarbons, andvarious syntheticlubricants. Specific examples of suitable synthetics include aliphaticdiesters (such as di-Z-ethyl hexyl azelate) silicate esters (such ashexa-Z-ethyl butoxy disiloxane) and poly allrylene glycols or theirether derivatives. In cases where the product of this invention is to beused as an additive to mineral oils, the carrier will usually be amineral oil such as a solvent refined Mid-Continent lubricating oil ofS.S.U. at 100 F. Similarly, if the product is to be used in syntheticoils, the vehicle will usually be a synthetic lubricant.

ALCOHOL SOLUTIONS OF INORGANiC BASE The suitable calcium containing baseis restricted to thev reaction product between hydrogen sulfide andcalcium hydroxide, its hydrates, and calcium oxide. The exact chemicalnature of this reaction product is uncertain owing to side reactions butthe principal ingredient is believed to be calcium sulfhydrate.

Only a few aliphatic alcohols are suitable for'use in the process of myinvention because of limited solubility for the reaction product betweenhydrogen sulfide and calcium hydroxide or calcium oxide. These includealcohols of the aliphatic primary series wherein the number of carbonatoms varies from 1 to 6. Of these alcohols, I generally prefermethanol, because itis available at a more economical price than theotheralcohols; and furthermore it may be more easily removed from thefinal product.

The process may be carried out using anhydrous alcohols and otherreactants or in the presence of water. The fact that water can betolerated is advantageous under certain conditions because many timescommercial products cannot be obtained in an anhydrous condition;furthemore, the reaction between hydrogen sulfide and calcium hydroxideor calcium oxide causes a certain amount of water to be formed. Inaddition, if the surface active agent is added as an acid, a certainamount of water willbe formed by the neutralization reaction.

The aliphatic alcohol and the calcium hydroxide or calcium oxide may beadmixed at room temperature, but should be cooled before reacting withhydrogen sulfide. Thispractice is desirable because the reaction .isexothermic and the product is unstable at elevated temperatures. Inpractice, I pr'e-cool the aliphatic alcohol slurry of calcium hydroxideor calcium oxide to a temperature of 59? F. or below before admittinghydrogen sulfide to the mixture. Cooling is normally continuedthroughout the reaction and the-hydrogen sulfide addition rate isadjusted so that the'temp'eratu'reof-the reaction mass does not exceed115 F. As the lime or calcium hydroxide is consumed, the heat ofreaction subsides and the reaction mass is cooled to a temperature of 53F. or below. At this point it is necessary to filter the aliphaticalcohol solution of the calcium inorganic base produced by this reactionin order to remove unreacted solids and/or solid byproducts.

The filtered reaction product is added with agitation to the dispersingagent, solvent, and non-volatile vehicle. The resulting mass is thenblown with CO until complete conversion to calcium carbonate isachieved. This is normally indicated by the absence 'of hydrogen sulfidein the efiluent gas stream when tested with moistened lead acetatepaper. Following carbonation, the volatile solvents and water arenormally removed by evaporation. The evaporation of the solvents may becaused by the application of heat or they may be removed by theapplication of a vacuum, in which case it is not necessary to heat themixture above room temperature. After the solvents have been removed,the product is optically bright. Neither centrifuging nor filtering isnecessary.

All of the base numbers of the products of this invention weredetermined by the acetic acid titration method which utilizes glacialacetic acid as the solvent and a solution of perchloric acid in glacialacetic acid as the titrant. The method is especially adapted fordeterminations of this type, since equilibria are obtained rapidly. Theprocedures for carrying out acetic acid titrations are generallyoutlined in Analytical Chemistry, vol. 23, No. 2, February 1951, page337, and vol. 24, No. 3, March 1952, page 519.

In order to disclose the nature of the present invention still moreclearly, the following illustrative examples will be given in whichparts used are parts by weight. In the examples the numerical valuepreceding pale oil designates the S.S.U. value at 100 F.

Example 1 One hundred and six parts of calcium hydroxide was added tosix hundred parts of methanol and the resulting slurry cooled to 59 F.This slurry was blown exhaustively with hydrogen sulfide during whichtime the temperature was not allowed to rise above 115 F. When thetemperature of the reaction mass was reduced to 43 F. by externalcooling, the intermediate product was filtered to remove unreactedsolids. The product from this reaction was a clear dark green solutionhaving a base number of 192 and an analysis of 6.8 percent calcium and13.2 percent sulfur. This intermediate was essentially stable whenstored for 8 hours in a closed container at room temperature, and formore than 30 days when stored in a closed container at 34 F. Threehundred parts of this product was admixed at room temperature with asolution consisting of 400 parts of a postdodecylbenzene sulfonic acidsolution in naphtha (sulfonic acidity=0.510 milli-equivalent per gram,naphtha content 68 weight percent), 312 parts of 170 pale oil, and 600parts of benzene. Carbon dioxide was passed at room temperature throughthe resultant mixture until no hydrogen sulfide was detectable in theelfiuent gas stream. The mass was then agitated while the temperaturewas gradually raised to 302 F. to remove the volatile solvents andwater. The resulting product was a bright liquid, had a base number of105, and analyzed 4.11 percent calcium and 1.69 percent sulfur.

Example 2 Forty-eight parts of calcium oxide was added to 600 parts ofethanol and the resulting slurry cooled to 50 F. This slurry was blownwith hydrogen sulfide during which time the temperature was not allowedto rise above 109 F. When the temperature of the reaction mass wasreduced to 53 F. by external cooling, the intermediate was filtered. Theproduct from this reaction had a base number of 107 and analyzed 3.8percent calcium and 7.3

Example 3 The procedure of Example 2 was followed with the exceptionthat the aliphatic alcohol used was n-butanol. The base number of theintermediate product was 43. Three hundred forty parts of theintermediate product was admixed with one hundred partspostdodecylbenzene sulfonic acid solution (sulfonic acidity=0.51milli-equivalent per gram, naphtha content 68 weight percent), 60 partsof 170 pale oil, and 175 parts of benzene. This mixture was treated asillustrated in the procedure of Example 2. The final product was abright fluid with a base number of 64.

Example 4,

The procedure of Example 3 was followed with the exception that thealiphatic alcohol used was isobutanol. The base number of theintermediate product was 40. The final product from the intermediate wasa bright fluid and had a base number of 61.

Example 5 The procedure of Example 3 was followed with the exceptionthat the aliphatic alcohol used was n-hexanol. The base number of theintermediate product was 37. The final product from this intermediatewas a bright fluid and had a base number of 59.

Example 6 Que hundred ninety-two parts of calcium oxide was added to3,000 parts of methanol and the resulting slurry cooled to 55 F. Thisslurry was blown exhaustively with hydrogen sulfide during which timethe temperature was not allowed to rise above F. When the temperature ofthe reaction mass was reduced to 43 F. by external cooling, theintermediate product was filtered. The product from this reaction was aclear dark green liquid that had a base number of 105 and analyzed 3.75percent calcium and 7.21 percent sulfur. Twenty-six hundred parts ofthis product was admixed with 1345 parts of a postdodecylbenzenesulfonic acid solution (sulfonic acidity=0.61 milli-equivalent per gram,naphtha content 68 weight percent), 1540 parts of pale oil, and 2600parts of benzene. Carbon dioxide was passed through the mixture until nohydrogen sulfide was detectable in the effluent gas stream. The mass wasthen agitated and the temperature gradually increased to 302 F. toremove the volatile solvents and water. The reaction mass was blown withcarbon dioxide for 15 minutes at this temperature to facilitate residualsolvent removal. The resulting product was a bright fluid having a basenumber of 98, and analyzed 4.06 percent calcium and 1.65 percent sulfur.

Example 7 The procedure of Example 6 was followed with the exceptionthat after removal of the solvents the mix-.

Example 9 The procedure of Example 6 was followed up to and includingthe intermediate preparation, however, one change was made in thematerial charge used to prepare the final product. This change consistedof using 3514 parts of n-pentane as the volatile solvent. Followingremovalfo hydrogen sulfide by blowing the reaction mass with carbondioxide, the solvents were removed from the'mixture by the applicationof a high vacuum. The maximum temperature attained during the removal ofsolvents was 109 F. and the minimum pressure was .15 mm.-of mercury. Theresulting product was abright fluid, had a base number of 98', andanalyzed 4.06 per cent calcium and 1.66 percent sulfur.

Example 10 A mixture consisting of 1611 parts of postdodecylbenzenesulfonic acid solution (sulfonic acidity 0.75 milli-equivalent per gram,66 weight'perccnt naphtha), 3000 parts benzene, and 3000 parts of amethanolic solution of the reaction product between calcium oxide andhydrogen sulfide having a base number of 109 was blown with carbondioxide until hydrogen sulfide evolution was complete. After carbonation1737 parts of hexa (2-cthyl butoxy) disiloxane was added to the reactionmass. The procedure of Example 6 was followed in removing the volatilesolvents. The resulting product was a bright fluid, had a base number of102, and analyzed 4.37 percent calcium and 1.48 percent sulfur.

Example 11 A mixture consisting of 1345 parts of postdodecylbenzenesulfonic acidsolution (sulfonic acidity 0.61 milli equivalent per gram,68 weight percent naphtha), 2600 parts of benzene, and 2600 parts of amethanolic solution of the reaction product between calcium oxide andhydrogen sulfide having a base number of 100 was blown with carbondioxide until hydrogen sulfide evolution was complete. After carbonation1543 parts of di-Z-ethyl hexyl azelate was added to the reaction mass.The procedure of Example 6 was followed in removing the volatilesolvents. The resulting product was a bright liquid, had a base numberof 98, and analyzed 4.06 percent calcium and 1.65 percent sulfur.

Example 12 A mixture consisting of 200 parts of ethylene diamine dinonylnaphthalene sulfonate (50 percent active in mineral oil) available underthe trade name of Na Sul EDS, 250 parts of benzene, 100 parts of 170pale oil,

and 230 prats of a methanolic solution of the reaction product betweencalcium oxide and hydrogen sulfide haveasiest ing a base number of11'8'was blow with'carbon'dioxid until hydrogen sulfide evolution wascomplete. The can bonatcd product was then treated as in Example 6. Thefinal product was a bright fluid, and had a. base numbe of 78. v

Example 14 I The procedure of Example 13 was repeated with the exceptionthat 200 parts of neutral barium dinonyl naphthalene sulfonate (50percent active in mineral oil) available under the trade name of Na SulBSN was employed instead of Na Sul EDS." The final product was a brightfluid and had a base number of 81.

Although the finished product comprising the oil,the surface activeagent, and the inorganic compound appears to the naked eye to be a truesolution, a careful examination shows that the inorganic compound existsas a dispersoid in the other components. For example, electionmicrographs indicate that the average diameter of the dispersedparticles range from about 0.007 to less than 1 micron with the greaterportion of the particles less than 0.03 micron in diameter. The productsof Examples 6 to 9, inclusive, were subjected to infrared examination.This examination showed the presence of an alkaline earth metalsulfonate and an alkaline earth. metal carbonate. Obviously, since theonly alkaline earth metal employed in the preparation of these productswas calcium, the presence to calcium carbonate as a dispersoid in thecomposition is indicated.

Lubricating compositions were prepared utilizing the product prepared inaccordance with the various examples listed herein. Since the resultsusing the various compounds are very similar, a lubricating oilcomposition using the product of Example 6 will be given forillustrative purposes. In preparing the compounding lubricating oil,suitable and preferred ranges of the different components vary asfollows: the product of Example 6, l to 20 percent, 2 to 6 percent; thecalcium-barium phenolate sulfide, 0.25 to 3 percent, 0.75 to 2 percent;metal dithiophosphate, 0.3 to 3 percent, 0.75 to 2 percent;methyldichlorostearate, 0.1 to 1 percent, 0.25 to 0.75 percenLrespectively; and sufiicient lubricating oil make percent. Thecalcium-barium phenolate sulfide, the metal dithiophosphate, and themethyl dichlorostearate are well-known commercially available materialswhich have been found to be compatible with my calcium carbonatedispersion. The calcium-barium phenolate sulfide serves as an oxygeninhibitor, the metal dithiophosphate serves as a metal deactivator toreduce corrosion and to minimize metal-catalyzed oxidation of thelubricating composition. The methyl dichlorostearate enhances theoiliness and film strength of the lubricant.

The oil base with which the foregoing additivesare blended is preferablyof a high viscosity index and highly refined mineral lubricating oilsblended to the various SAE viscosity number requirements. For example,the oil blends which have been used in producing the im provedlubricating compositions of this invention may be prepared fromMid-Continent solvent refined and distillation oil fractions to providea viscosity index of about 98 and a sulfur content not exceeding about0.1 percent.

The character of the base oil is such that with the added componentsabove described, the finished composition should have a base numberof atleast about 2.0 and preferably not less than about 3.0, thus providingan engine lubricant with an actively available alkaline reserve forneutralizing service-developed corrosively acidic oxidation products.

These lubricating compositions may also have added thereto, as iscommonly done, an antifoaming agent, a pour point depressant, aviscosity index improver, all of which have been found generallycompatible in the foregoing described lubricating compositions.

' An oil composition of SAE 10-W viscosity prepared in. accordance withthis invention contained the following:

Additives:

4.0 parts of the dipersed-CaCO; sulfonate detergent of Example 6 1.0part of Ca-Ba phenolate sulfide 1.25 parts of' Zndi (alkyl phenyl)dithiophosphate 0.40 part methyl dichlorostearate Mineral oil base:

8.16 parts neutral 100 pale oil 91.84 parts neutral 170 pale oil Theforegoing lubricating composition and the base oil blend withoutadditives were run in a Chevrolet L-4 test under the following engineconditions:

Sp r.p.m 3150 Lo H P 30 Oil sump temperature F-.. 280 Water jackettemperature F 200 Additives:

500. weight percent of the disposed CaCO sulfonate detergent of Example6 1.25 weight percent zinc di (alkyl phenyl) dithiophosphate .001 weightpercent di methyl poly siloxane Mineral oil base:

8.16 weight percent neutral 100 pale oil 91.84 weight percent neutral170 pale oil The foregoing lubricating composition and the base oilblend were run in a four-cylinder Cub engine (Internationals lighttractor engine adapted to a test stand) under the following testconditions:

Speed r.p.m.... 2500 T nad H P 6,5 Oil sump temperature F 280 Waterjacket temperature F 200 Running tim urs 36 After completion of the testthe engines were disassembled and the parts inspected and assigneddemerit ratings on their condition. The lower the total demerit ratings,the better is the general engine condition and the oil performance. Arating below 10 is considered to be excellent and a rating between 10and is good. Corrosion is also measured by weighing the bearing shellsbefore and after the runs. A loss due to corrosion of less than 0.05gram is considered satisfactory. The results of this engine testutilizing my new additive showed a total demerit rating of 8.5 dividedas follows: piston skirts 1.0, varnish 4.5, sludge 1.5, and carbon 1.5.The average one half bearing weight loss was 0.0065. gram. The base oilblend used in the foregoing lubricating composition had a total demeritrating of 18.0 divided as follows: piston skirts 2.0, varnish 10.5,sludge 2.5, and carbon 3.0. The average one half bearing weight loss was0.1891 gram.

The foregoing lubricating composition was also tested in diesel enginesusing fuel containing 1 percent sulfur. The use of high sulfur fuelsgreatly accelerates the formation of piston ring and skirt deposits,hence shortening the running time required for detergent evaluation.

The engine used for this evaluation .wasa ;Witte diesel run under thefollowing operating conditions:

' The condition of the piston is examined upon completion of the run,and assigned a demerit rating. A Witte piston rating below 8 isconsidered to be excellent. Those between 8 and 15 are considered to begood to fair, and indicate satisfactory performance. A rating above 20indicates unsatisfactory performance. In this test the engine utilizingmy new additive in the previously described lubricating oil compositionshowed a demerit rating of 3.0 (varnish 2.5, carbon 0.5).. The nearestcompetitive oil had a demerit rating of 9.0 (varnish 5.0, carbon 4.0).

As pointed out above, neither is involved heat treatment nor filtrationof the final product necessary in the preparation of the product of myinvention as contrasted to the process of the prior art. These facts arebrought out by Examples 6 through 9, inclusive As for example, Example 7is a duplicate of Example 6 with the exception that the product ofExample. 7 was filtered. The final products obtained ineach example werevery similar, and photographs of the products taken at a magnificationof 21,000 diameters showed them to be practically identical. Example 8was also a duplicate of Example 6 with the exception that one percentwater was added to the composition prior to carbonation. Again the finalproducts were practically identical and photographs taken at amagnification of 21,000 diameters showed them to be identical. Theprocedure used in Example 9 was the same as that employed in Example 6except that the solvents were removed under vacuum which made itpossible to carry out the entire procedure at a maximum temperature of109 F. I Again the product obtained was similar to the product obtainedin Example 6. These examples show three things: (1) filtraber and-theamount of calcium present in excess over that present in the oil solubledispersing agent alone. Tabulated below are data showing thisrelationship in dispersions of calcium carbonate in a non-volatilecarrier wherein the base number varies from 30 to 125. In all cases theratio of neutral calcium postdodecylbenzene sulfonate to non-volatilecarrier was maintained equivalent to that of a, base number product.

Basic Calcium B.N. Percent Basic Percent Neu- (Percent of Calcium tralCalcium Neutral Calcium) This application is a continuation-in-part ofmy copending application, Serial No. 362,970,. filed June 19, 1953, nowabandoned.

While particular embodiments of the invention have been described, itwill be understood, of course, that the invention is not limited theretosince many modifications may be made, and it is, therefore, contemplatedto cover by the appended claims any such modifications as fall withinthe true spirit and scope of the invention.

spam-9i "The invention having thus been described, what is claimed anddesired to be secured by Letters Patent is:

1. The process of forming a stable dispersion of calcium carbonate in anon-volatile carrier which comprises:

A. Admixing under atmospheric conditions of temperature and pressure (1)an oil soluble dispersing agent selected from the class consisting ofsulfonic acids, metal sulfonates, ammonium sulfonates, and amine sul--fonates wherein the molecular weight of the hydrocarbon portion of saiddispersing agent varies from 350 to 1000 a volatile hydrocarbon solventfor said oil soluble dispersing agent a non-volatile carrier selectedfrom the class consisting of mineral lubricating oils and syntheticlubricants for said oil soluble dispersing agent an aliphatic alcoholsolution wherein the alcohol contains from 1 to 6 carbon atoms, of anoil insoluble calcium inorganic base consisting of the reaction productbetween hydrogen sulfide and a calcium inorganic compound wherein theanion of said compound is selected from the group consisting of oxideand hydroxide radicals and characterized further in that the amount ofsaid inorganic base varies from about 1% to 4% times that required toreactwith the sulfonic acid where this material is' used as dispersingagent and V2 to 3% times the number of chemical equivalents of thedispersing agent where said dispersing agent is a salt of a sulfonicacid Condensing from the resulting mixture at atmospheric pressure anoil-insoluble calcium carbonate in particles, the diameters of which areless than 0.25 micron, by passing carbon dioxide through said mix- .tureto convert the excess calcium inorganic base to carbonate, and then C.Removing the residual solvents by evaporation.

2. The process of claim 1 wherein the oil soluble dis persing agent is asulfonic acid wherein the hydrocarbon portion of said sulfonic acid hasa molecular weight between 400 and 700.

3. The process of claim 1 wherein the oil soluble dispersing agent. ispostdodecylbenzene sulfonic acid.

4. The. process of. claim 1 wherein the oil soluble dispersing agent is:an alkaline: earth metal postdodecyl benzene sulfonate.

5. The process of claim 1 wherein the oil solubledispersing, agent isbarium postdodecylbenzene sulfonate.

. 6. The process of claim 1 wherein the oil soluble dispersing agent iscalcium postdodecylbenzenesulfonate.

7. The process of claim 1 whereinthe non-volatilecarrier is a minerallubricating oil.

8. The process of claim 1 wherein the non-volatile carrier is asynthetic lubricating oil.

9. The process of claim 1 wherein the non-volatile carrier isdi-iso-octyl azelate.

10. The process of claim 1 wherein the non-volatile carrier ishexa(2-ethylbutoxy)disiloxane.

11. The process of claim 1 wherein the aliphatic alcoholic solution is amethanolic solution.

12. The process of claim 1 wherein the aliphatic alcoholic solution isan ethanolic solution.

13. The process of claim 1 wherein the aliphatic alcoholic solution is an-butanolic solution.

14. The process of claim 1 wherein the alcoholic solution is anisobutanolic solution.

15. The process of claim 1 wherein the alcoholic solution is an-hexanolic solution.

16. The process of claim 1 wherein the calcium inorganic compound iscalcium oxide.

17. The process of claim 1 wherein the calcium inorganic compound iscalcium hydroxide.

18. The process of claim 1 wherein the oil-soluble dispersing agent is ametal sulfonate and the hydrocarbon portion of said sulfonate has amolecular weight between 400 and 700.

19. The process of claim 1 wherein (1) the dispersing agent ispostdodecylbenzene sulfonic acid, (2) the nonvolatile carrier is amineral lubricating oil, and (3) the alcoholic solution of anoil-insoluble calcium inorganic base is a methanolic solution.

20. The process of claim 1 wherein (1) the dispersing agent is analkaline earth metal postdodecylbenzene sulfonate, (2) the non-volatilecarrier is a mineral lubricating oil, and (3) the alcoholic solution ofan oil-insoluble calcium inorganic base is a methanolic solution.

21. The process of claim 1 wherein 1) the dispersing aliphatic aliphaticagent is postdodecylbenzene sulfonic acid, (2) the mm volatile carrieris a synthetic lubricant, and (3) the alcoholic solution of anoil-insoluble calcium inorganic base is a methanolic solution.

22. The process of claim 1 wherein (1) the dispersing agent is analkaline earth metal postdodecylbenzene sulfonate, (2) the non-volatilecarrier is a synthetic lubricant, and (3) the alcoholic solution of anoil-insoluble calcium inorganic base is a methanolic solution.

References Cited in the file of this patent UNITED STATES PATENTS2,079,051 Sullivan et al'. May 4, 1937 2,413,311 Cohen Dec. 31, 19462,417,428 McLennan Mar. 18, 1947 2,501,732 Mertes Mar. 28, 19502,585,520 Van Ess Feb. 12, 1952 2,676,925 Lindstrom Apr. 27, 1954

1. THE PROCESS OF FORMING A STABLE DISPERSION OF CALCIUM CARBONATE IN ANON-VOLATILE CARRIER WHICH COMPRISES: A. ADMIXING UNDER ATMOSPHERICCONDITIONS OF TEMPERATURE AND PRESSURE (1) AN OIL SOLUBLE DISPERSINGAGENT SELECTED FROM THE CLASS CONSISTING OF SULFONIC ACIDS, METALSULFONATES, AMMONIUM SULFONATES, AND AMINE SULFONATES WHEREIN THEMOLECULAR WEIGHT OF THE HYDROCARBON PORTION OF SAID DISPERSING AGENTVARIES FROM 350 TO 1000 (2) A VOLATILE HYDROCARBON SOLVENT FOR SAID OILSOLUBLE DISPERSING AGENT (3) A NON-VOLATILE CARRIER SELECTED FROM THECLASS CONSISTING OF MINERAL LUBRICATING OILS AND SYNTHETIC LUBRICANTSFOR SAID OIL SOLUBLE DISPERSING AGENT (4) AN ALIPHATIC ALCOHOL SOLUTIONWHEREIN THE ALCOHOL CONTAINS FROM 1 TO 6 CARBON ATOMS, OF AN OILINSOLUBLE CALCIUM INORGANIC BASE CONSISTING OF THE REACTION PRODUCTBETWEEN HYDROGEN SULFIDE AND A CALCIUM INORGANIC COMPOUND WHEREIN THEANION OF SAID COMPOUND IS SELECTED FROM THE GROUP CONSISTING OF OXIDEAND HYDROXIDE RADICALS AND CHARACTERIZED FURTHER IN THAT THE AMOUNT OFSAID INORGANIC BASE VARIES FROM ABOUT 1 1/2 TO 4 1/2 TIMES THAT REQUIREDTO REACT WITH THE SULFONIC ACID WHERE THIS MATERIAL IS USED ASDISPERSING AGENT AND 1/2 TO 31/2 TIMES THE NUMBERE OF CHEMICALEQUIVALENTS OF THE DISPERSING AGENT WHERE SAID DISPERSING AGENT IS ASALT OF A SULFONIC ACID B. CONDENSING FROM THE RESULTING MIXTURE ATATMOSPHERIC PRESSURE AN OIL-INSOLUBLE CALCIUM CARBONATE IN PARTICLES,THE DIAMETERS OF WHICH ARE LESS THAN 0.25 MICRON, BY PASSING CARBONDIOXIDE THROUGH SAID MIXTURE TO CONVERT THE EXCESS CALCIUM INORGANICBASE TO CARBONATE, AND THEN C. REMOVING THE RESIDUAL SOLVENTS BYEVAPORATION.